Studies on homologous recombination in the green alga Chlamydomonas reinhardtii

The introduction of exogenous DNA into the nuclear genome of Chlamydomonas reinhardtii occurs predominantly via non-homologous (illegitimate) recombination and results in integration at apparently-random loci. Using truncated and modified versions of the C. reinhardtii ARG7 gene in a series of transformation experiments, we demonstrate that homologous recombination between introduced DNA molecules occurs readily in C. reinhardtii, requires a region of homology of no more than 230 bp, and gives rise to intact copies of ARG7 in the nuclear genome. Evidence is presented for homologous recombination between introduced ARG7 DNA and the resident copy of the gene, and for the de-novo synthesis of the ARG7 sequence during transformation.     

C3 promotes clearance of Klebsiella pneumoniae by A549 epithelial cells

The airway epithelium represents a primary site for contact between microbes and their hosts. To assess the role of complement in this event, we studied the interaction between the A549 cell line derived from human alveolar epithelial cells and a major nosocomial pathogen, Klebsiella pneumoniae, in the presence of serum. In vitro, we found that C3 opsonization of poorly encapsulated K. pneumoniae clinical isolates and an unencapsulated mutant enhanced dramatically bacterial internalization by A549 epithelial cells compared to highly encapsulated clinical isolates. Local complement components (either present in the human bronchoalveolar lavage or produced by A549 epithelial cells) were sufficient to opsonize K. pneumoniae. CD46 could competitively inhibit the internalization of K. pneumoniae by the epithelial cells, suggesting that CD46 is a receptor for the binding of complement-opsonized K. pneumoniae to these cells. We observed that poorly encapsulated strains appeared into the alveolar epithelial cells in vivo but that (by contrast) they were completely avirulent in a mouse model of pneumonia compared to the highly encapsulated strains. Our results show that bacterial opsonization by complement enhances the internalization of the avirulent microorganisms by nonphagocytic cells such as A549 epithelial cells and allows an efficient innate defense.     

Characterization of Aeromonas caviae antigens which cross-react with Shigella boydii 5.

Live and boiled cells of 16 strains of Aeromonas caviae, isolated from patients with diarrhea, agglutinated with Shigella boydii 5 antiserum in a slide test. Further studies with seven selected strains showed agglutination with boiled cells in a tube test. Lipopolysaccharide antigen extracted from one of these strains cross-reacted with S. boydii 5 in enzyme-linked immunosorbent assay and immunoblot studies. Either all or the majority of the seven strains possessed properties deemed to be diarrheagenic.     

Metachronous and multiple aneurysmal bone cysts: a rare variant of primary aneurysmal bone cysts

In 1942, Jaffe and Lichtenstein introduced the term aneurysmal bone cyst (ABC). Primary ABC is characterized by the presence of spongy or multi-cameral cystic tissue filled with blood. The process is benign, but it is locally destructive and has a high propensity for recurrence. In this paper, we present the third case of multiple metachronous primary ABCs as a rare variant of ABC. We describe the 10-year history of a 12-year-old boy with metachronous multiple primary ABCs at five different sites (right proximal humerus, right ulna, bilateral distal radius and right lateral clavicle). Furthermore, our patient suffered from vascular malformations, such as aortic isthmus stenosis, hypoplastic thoraco-abdominal aorta and bilateral renal artery stenosis. To date, in contrast to solitary ABC, the multiple lesions have been found more frequently in male individuals. Using interphase cytogenetics, we analyzed three of five of the patients ABCs and one of these was also analyzed by GTG-banding. No chromosomal abnormalities were found. Significantly, we excluded the missense mutation of codon 201 in guanine nucleotide-binding protein 1 gene consistently found in McCune-Albright syndrome (MAS) and in non-MAS cases of polyostotic fibrous dysplasia of bone with or without secondary ABC.     

Results of a high-resolution genome screen of 437 Alzheimer's disease families

Alzheimer's disease (AD) is a devastating neurodegenerative disorder of late life with complex inheritance. Mutations in three known genes lead to the rare early-onset autosomal dominant form of AD, while a common polymorphism (epsilon 4) in the gene encoding apolipoprotein E (APOE ) is a risk factor for more typical late-onset (>60 years) AD. A recent study concluded that there are up to four additional genes with an equal or greater contribution to the disease. We performed a 9 cM genome screen of 437 families with AD, the full National Institute of Mental Health (NIMH) sample, which has been carefully ascertained, evaluated and followed by our group over the last decade. Performing standard parametric and non-parametric linkage analyses, we observed a 'highly significant' linkage peak by Lander and Kruglyak criteria on chromosome 19q13, which probably represents APOE. Twelve additional locations-on 1q23, 3p26, 4q32, 5p14, 6p21, 6q27, 9q22, 10q24, 11q25, 14q22, 15q26 and 21q22-met criteria for 'suggestive' linkage [i.e. two-point lod score (TLS) >/=1.9 and/or multipoint lod score (MLS) >/=2.2] in at least one of our analyses. Although some of these will surely prove to be false positives, these linkage signals should provide a valuable framework for future studies aimed at identifying additional susceptibility genes for late-onset AD.     

Monoclonal antibodies to the enterotoxin of Bacteroides fragilis: production, characterization, and immunodiagnostic application.

A monoclonal antibody, ICT11, specific for the toxin of enterotoxigenic Bacteroides fragilis (ETBF) neutralized the cytotoxic effect of the toxin on human colonic cell line HT-29/C1. In an evaluation using 115 diarrheal stool specimens and culture as the "gold standard," the assay showed a sensitivity of 85% and a specificity of 100%. An ICT11-based sandwich enzyme-linked immunosorbent assay showed a sensitivity of 100% and a specificity of 98% for direct detection of toxin from stool samples compared with those of culture. Thus, ICT11-based assays will be useful for screening for ETBF.     

Schistosomiasis: an unusual cause of tubal infertility

A case report of a Nigerian woman having an unusual cause oftubal infertility is presented. On histological examinationof the Fallopian tube, ova of Schistosoma haematobium enclosingliving miracidia were found in the smooth muscle layer of theFallopian tube and its mesosalpinx. Mechanisms of tubal involvementare analysed. The case indicates the need to consider schisto-somiasisas a possible aetiological factor in patients with tubal infertilitycoming from areas where the disease is endemic.     

Adapting industry-style business model to academia in a system of Performance-based Incentive Compensation.

Performance-Based Incentive Compensation (PBIC) plans currently prevail throughout industry and have repeatedly demonstrated effectiveness as powerful motivational tools for attracting and retaining top talent, enhancing key indicators, increasing employee productivity, and, ultimately, enhancing mission-based parameters. The University of Arkansas for Medical Sciences (UAMS) College of Medicine introduced its PBIC plan to further the transition of the college to a high-performing academic and clinical enterprise. A forward-thinking compensation plan was progressively implemented during a three-year period.After the introduction of an aggressive five-year vision plan in 2002, the college introduced a PBIC plan designed to ensure the retention and recruitment of high-quality faculty through the use of uncapped salaries that reflect each faculty member's clinical, research, and education duties. The PBIC plan was introduced with broad, schoolwide principles adaptable to each department and purposely flexible to allow for tailor-made algorithms to fit the specific approaches required by individual departments.As of July 2006, the college had begun to reap a variety of short-term benefits from Phase I of its PBIC program, including increases in revenue and faculty salaries, and increased faculty morale and satisfaction.Successful implementation of a PBIC plan depends on a host of factors, including the development of a process for evaluating performance that is considered fair and reliable to the entire faculty. The college has become more efficient and effective by adopting such a program, which has helped it to increase overall productivity. The PBIC program continues to challenge our faculty members to attain their highest potential while rewarding them accordingly.     

Reproducibility of Immunological Tests Used To Assess Multiple Chemical Sensitivity Syndrome

Whether persons with multiple chemical sensitivity syndrome (MCS) have immunological abnormalities is unknown. To assess the reliability of selected immunological tests that have been hypothesized to be associated with MCS, replicate blood samples from 19 healthy volunteers, 15 persons diagnosed with MCS, and 11 persons diagnosed with autoimmune disease were analyzed in five laboratories for expression of four T-cell surface activation markers (CD25, CD26, CD38, and HLA-DR) and in four laboratories for autoantibodies (to smooth muscle, thyroid antigens, and myelin). For T-cell activation markers, the intralaboratory reproducibility was very good, with 90% of the replicates analyzed in the same laboratory differing by ≤3%. Interlaboratory differences were statistically significant for all T-cell subsets except CD4⁺ cells, ranging from minor to eightfold for CD25⁺ subsets. Within laboratories, the date of analysis was significantly associated with the values for all cellular activation markers. Although reproducibility of autoantibodies could not be precisely assessed due to the rarity of abnormal results, there were inconsistencies across laboratories. The effect of shipping on all measurements, while sometimes statistically significant, was very small. These results support the reliability of fresh and shipped samples for detecting large (but perhaps not small) differences between groups of donors in the T-cell subsets tested. When comparing markers that are not well standardized, it may be important to distribute samples from different study groups evenly over time.